Can science prove anything, and can we “prove” the comprehensible input hypothesis?

The answer: science can never prove anything. Truth, technically, is a property of closed symbolic systems (e.g. logic, math). So, why– how?— is science useful? It’s pretty simple. All science does is make testable predictions about causes of phenomena. Sometimes, scientists will also propose an actual mechanism.

Scientists:

observe a phenomenon (e.g. people acquiring languages)

make a prediction/guess about how this happens (e.g. via comprehensible input). This is called forming a hypothesis

test via experiment your hypothesis to confirm it (e.g. expose people to comprehensible input and see whether or not they learn the language; expose them to grammar lessons and see whether/how well they acquire)

At the end of your experiment, you will know whether or not X causes Y.

For it to qualify as science, an experiment has to repeatedly generate the same results.

Krashen’s hypothesis is simple: if people are exposed to comprehensible input in the target language, they will acquire the language. (Technically, Krashen’s hypothesis– which has been tested and confirmed– is now a theory.)

Steve Smith has two objections to Krashen’s hypothesis. First, he says this:

Strictly speaking, no hypothesis can ever be “proven” true. All you can do is test the hypothesis and see whether data confirms it (aligns with its predictions). With language acquisition, the research is clear: people who get comprehensible input acquire languages; people who get incomprehensible input, grammar practice, too much output “practice,” or a mix of all acquire no (or very little) language, and always much less than those exposed to comprehensible input.

Is the hypothesis testable? Yes. Has it been tested, and its predictions confirmed? Yes. Has anything else come along to provide a better explanation? No(t yet). Karl Popper reminds us that good science isn’t true. He notes that good science has only two properties:

it’s just not wrong (yet)

it makes accurate, testable predictions.

While Smith is technically correct, he misses the point. Suppose we hypothesise that an analgesic such as Ibuprofene reduces pain. On testing our hypothesis, we find that it does indeed reduce pain. The confirmed hypothesis is thus useful and accurate, but, technically, it’s not “true.” It “does the job” of explaining and predicting. Hypotheses aren’t true— they work, or they don’t.

Smith’s second claim is this:

This misses the point entirely. First, Krashen does not propose an explanation for language acquisition on the neurological level, nor does he need to. His hypothesis only involves comprehensible input and acquisition (both of which he defines).

An analogy may be of service here. Imagine: we bring a preindustrial tribesman into the modern world and he observes cars. He forms a hypothesis– gas makes cars go– and predicts that, ceteris paribus, a car with a full gas tank will go further than a car with an empty tank, and tests this hypothesis. The car’s performance obviously substantiates his hypothesis. Now, the fact that the tribesman doesn’t know anything about internal combustion engines, energy efficiency, math, etc, while true, is irrelevant and does not discredit his hypothesis.

Similarly, the fact that Krashen (and Chomsky, and VanPatten, and Lightbrown, and every other person who investigates S.L.A.) do not propose a neurological explanation for language acquisition is irrelevant. What counts is whether or not the hypothesis holds up under experimental scrutiny (i.e. whether or not people acquire language through comprehensible input).

Somebody could come along with a better explanation (in which case the comprehension hypothesis, as Krashen notes, gets tossed). Or, somebody could get right down to the neuronal level and explain the acquisitional mechanism. If this “neuronal explanation” showed that something other than c.i. accounted for SLA, the hypothesis would again get the boot. Or, it might simply show us the mechanism by which comprehensible input becomes acquisition. (This would be something like how Einstein updated Newton: relativity doesn’t invalidate Newtonian mechanics, rather, it just applies on a different level).

Second, Smith is wrong when he says there is no way to say whether or not the use of comprehensible input, focus on form (grammar instruction and/or practice) or a mix of the two are best practice in the language class. First, we know what works (comprehensible input) from research. Second, we know– again from research– what has no (or very limited, conscious-mind-only, and short term) effects: grammar teaching and practice, and output. Unless you want to advocate doing something that we know doesn’t work very well, the conclusion is obvious: the more c.i. learners get, the better off they will be, and the best mix is probably as little grammar talk as possible. VanPatten has also weighed in here, saying that traditional practice and grammar explanations do “very little” for acquisition.

Again, we don’t know for sure how much grammar instruction and how much input learners should be getting. There are a lot of suggestions, though. In the New Brunswick E.L.L. study (Lightbrown et al), French-speaking students who received only comprehensible input (by reading and listening) without a teacher did almost as well as students who were taught English and tutored in writing. In other words, 90+% of the work was done by input. Beniko Mason (1997) found that Japanese college students who simply read in English far outperformed students who had writing practice and direct grammar instruction in vocabulary recognition. In both first and second languages, free voluntary reading (teacherless comprehensible input, as it were) has overwhelmingly and repeatedly outperformed any other method of teaching vocabulary, grammar, style, etc (Krashen’s site has all the data).

[real-life digression: Blaine Ray told me the following: when T.P.R.S. was being developed in the late 1980s, Ray called Krashen– who was then with Tracy Terrell testing the “Natural Approach”– and asked, “how much grammar homework should I be doing?” Krashen, skeptical of grammar practice from his linguistics research but aware that there were also gaps in said research, told Ray “well, get them to do some grammar practice just for homework.” So, Ray– whose Bakersfield school district mandated grammar teaching– had his kids do the stupid fill-in-the-blanks stuff that comes with the ¡Díme! program– the cuaderno exercises. At the end of the year of grammar homework, Ray found the kids writing and saying basic errors like *Yo quiero juego fútbol americano (I want I play football– the sentence should read yo quiero jugar fútbol americano). Exasperated, thinking “why waste time?”, he ditched all the grammar homework, and next year, in class, while announcements blared and he had to take attendance, Ray had a kid stand at the front of the room, read the ¡Díme! grammar explanations aloud to fulfill District requirements (nobody listened), assigned reading for homework, and found the kids at the end of the next year making fewer mistakes.

This is an experience that every stick-to-your-guns T.P.R.S. teacher has had or will have. You will doubt the power of comprehensible input, you will assign grammar homework (or “conversation practice” or whatever legacy method), your kids will dutifully do this, and it won’t work.]

Third, Smith is also wrong when he says that because we cannot “see into [the] brain,” there is no way to decide what language class activities are best. We don’t need to “see into [the] brain” to know what works. You probably can’t explain on a chemical level what happens when your car burns gas. Do you need to in order to drive? I’d say, if you know enough to put the right fuel in, and you do put the right fuel in, you’re all set. And if you did know a chemical explanation for combustion, would that help you drive?

Smith also says this:

I didn’t say this, and the research flatly contradicts it. Krashen (2003) in “Explorations in Language Acquisition” notes that all the research on grammar-focused teaching shows positive effects only when assessment is done under Monitor-use conditions.

In other words, grammar teaches you…grammar. VanPatten comments that “what we call grammar rules are what we end up with, and are not how we learn or what the brain actually does” (MIWLA presentation, 2013), and the rest of the research is here.

Grammar-focused teaching works when

grammar items are either elicited and/or “overloaded” in the input

learners have time to think of and plan for responses

learners know, know how to apply, and have time to apply, the grammar rules

Krashen proposes a much higher standard for testing whether or not grammar teaching becomes implicit (automatic) learning (i.e. whether people have acquired the item in question), with broadly two criteria:

a) a three-months-delayed post-test. Most of the research will do an immediate treatment post-test (i.e. they will see if people can do/use grammar rule ______ right after the experiment) and a slightly delayed post test (e.g. two weeks later). However, if we waited three months, and grammar rule ____ was still recognised or put into use, then we would have much stronger evidence that explicit teaching can become implicit knowledge.

b) Monitor-free testing. This just means that you see whether people have picked up ______ without making them consciously aware that they have learned, should use, etc ____.

Say your treatment was teaching English speakers Spanish pronoun placement. Pronoun goes before one verb, or before or after verb clause w/ some exceptions, bla bla. This is a classic S.L.A. research area, because Spanish pronoun location is different from English, so it’s brainwork to acquire this new rule. Now, when you do your post-test, here are two possible scenarios:

1. You tell your test subjects “OK, we are gonna ask you some questions. A question might be ¿Conoces a George Clooney? and you could answer Sí, lo conozco or No, no lo conozco.” You could also (or instead) tell them “we would like you to answer using pronouns, like lo or la etc.”

2. You tell your test subjects “OK, we are going to ask you some questions, just answer.”

Under (1), we are modeling specific behaviours, reminding people about expectations and grammar rules, pronouns, etc. We are bringing grammar knowledge to conscious awareness. Under (2), we just see what they do. They might use pronouns, or not, or sometimes, or use them in a mix of properly and not, etc. Krashen’s point is very simple: if we do anything like (1), we are not necessarily seeing what people have acquired. We are seeing what people can do with conscious knowledge and/or modeling. This is what Krashen calls “Monitor use.”

Why do we want to have Monitor-free assessment of instructional treatment? Because, in the real world, we simply do not have time to think, rule-remember, edit, etc. Good language teaching will “wire the language in” below the level of conscious awareness. If I teach rock climbing, I don’t want you to be able to tell me how to tie a figure 8, or how to do a drop knee and lock-off; I want you to tie a figure 8, and automatically do a drop knee with lock-off when you need it. When I am at the Paris Metro and a smoking hot Parisienne is flirting with me, I need to be able to spit out, without thinking, right away, j’aimerais vous inviter à manger avec moi, parce-que vous êtes une femme incroyablement interesante or whatever. If I am standing there going “OK, do I put vous in front of or behind the inviter?” I am not going to have even a shot at the lady’s company.

OK, back to Steve Smith:

Smith also commits a few logical fallacies here.

First, the appeal to authority and mass opinion– that people “feel” something works– does not qualify as evidence that it does. I “feel” that the Moon is made of cheese. Is it?

Second, it’s also post hoc, ergo propter hoc— after this, because of this. You teach French grammar (and whatever else), and after that, your kids acquire some French. Was it the grammar, the “whatever else,” or both that got them to learn? Eric Herman and I have discussed what he calls “incidental learning,”, and we concluded this: even horrible languagen teaching– what I did for the first 12 years of my career– “works” because even if you are doing forced output, grammar worksheets, bla bla bla, the kids are getting comprehensible input. Boring, impoverished, low quantities, etc, but c.i. So…do Steve Smith (or whoever)’s kids acquire because of grammar, or because grammar contains some c.i.?

Third, Smith says that “learners” feel “conscious learning” can “become acquired.” Really? We’d need some evidence for this– i.e. Smith would have to ask say 100 students how well they felt that grammar teaching and practice was helping them, and then compare those statements with results, and show us that the students who liked their grammar teaching did significantly better (than controls) as a result, etc. Any T.P.R.S. teacher would respond to this by saying “we don’t spend more than 20 sec/class on grammar, and our kids feel that comprehensible input stories are the most effective way to learn ____.” Again…we’d need evidence from TPRS kids.

Another problem here: even if you “feel” grammar teaching helps, how do you know it does? This is much like the “noticing” argument that Swain developed and Truscott dismissed: the fact that you are aware of a form-meaning connection (a grammar point) which you’ve acquired does not mean that you acquired it because of this awareness. (In my experience, it’s the opposite: I “notice” grammar awareness once I have acquired it– your mileage may vary.)

The question of whether or not one could ever deliver “pure” grammar instruction is up in the air. I have said this before and I think Smith may be referring to that statement. Even T.P.R.S. is technically not 100% input– because we do occasionally say “-s means you in Spanish.”

Suppose you have a terrible book– Avancemos, say– where the kids have to conjugate “to go” in Spanish. So they are writing Yo voy al cine, ella va a la escuela, etc. Boring & dumb, and output as VanPatten reminds us is useless, etc. BUT…if the kids actually understand what they are reading, it is still (tedious, two-dimensional, impoverished) input. So, you could get them to pick up some Spanish that way. I guess. If you wanted to totally suck, and make your kids hate Spanish, and make them learn slowly, and check out emotionally…

VanPatten also notes that “what we call grammar rules are what we end up with, and are not how we learn or what the brain actually does” (MIWLA presentation, 2013), and that “classroom rule learning is not the same as acquisition.” Lightbown writes that “structured input works as well as structured input plus explanation” (in VanPatten, 2004): in other words, explanations don’t aid acquisition (though some students may feel good getting them).

Bardovi-Harlig (2000) found, as VanPatten and Wong put it, that “learners– again, both in and out of the classroom– have demonstrated that acquisition of the tense and aspectual systems (e.g. the use of the preterit/passé composé and the imperfect) is piecemeal and unaffected by instructional intervention.”

VanPatten (1998) also notes that “[a] reading of the literature on second language acquisition and use suggests that communication is not the result of learning discrete bits of language and then putting them together.“

VanPatten (2013) also echoes Susan Gross when he notes that “building up in a learner’s brain [are] simultaneously lexicon and morphology, syntatic features and constraints, pragmatics and discourse, interfaces between components, communicative discourse [and] skill” and that “these happen all at once. They are almost impossible to isolate and practice one at a time, because they don’t operate one at a time.“

In a fascinating study, Batterink & Neville (2013) found evidence that the “longstanding hypothesis is that syntactic processing occurs outside of conscious awareness, relying upon computational mechanisms that are autonomous andautomatic” (what Krashen calls the Monitor model) is, in fact, correct.

2) How much vocabulary, grammar and general language skill do students pick up via free voluntary reading (FVR)? LOTS…and loads more than from direct instruction. There are estimates that readers acquire an average of a word every twenty minutes of FVR, that FVR works about twenty times as quickly as classroom instruction, and that 75% of an adult’s vocabulary comes from reading. See Lehman (2007), summarised in IJFLTJuly07. Additional free voluntary reading research is detailed on Krashen’s site and Japanese researcher Beniko Mason has also done a ton of good FVR research. There is very good research on the Fijian Book Flood experiment detailed here, which shows, among other things, that some “focus on form”– grammar and writing feedback– is useful for second-language acquisition at later and higher levels, even while comprehensible input does 95% of the work and remains the sine qua non of language acquisition. In a recent study (abstract here), non-native speakers of Spanish who had a Spanish reading habit had much greater vocabulary than native Spanish speakers who did not read.

VanPatten writes that “for maximum vocabulary development, learners need to read all along the way, since most vocabulary development in both L1 and L2 is incidental, meaning that vocabulary is learned as a by-product of some other intention (normally reading).” Warwick Ely here examines free voluntary reading, grammar instruction, etc, and comes to the same conclusions that Krashen, VanPatten, Wong, Lightbown & Spada etc do. Waring (2015) here makes the “inescapable case” for reading. Mason and Krashen’s look at F.V.R. among Japanese learners of English showed significant positive effects.

Self-selected, comprehensible, interesting reading in the target (or native) language is boosts acquisition for the following reasons:

it delivers masses of comprehensible input

learners can pause, slow down, go back and seek extra (e.g. online or dictionary) help, which they cannot do nearly as well with a live speaker, and especially not with many native speakers (who often do not adjust vocabulary and speed to non-native-speakers’ needs)

for beginners, prosodic features like word differentiation are easier to see than to hear (but others, such as tone and accent, are harder to grasp)

the brain’s visual system is acute and, especially for monolinguals, better developed than the hearing processing system.

3) Do people acquire language via comprehensible input? YES. Krashen here summarises the comprehension hypothesis and destroys its rivals. Lightbrown and Spada (2013) state that “comprehensible input remains the foundation of all language acquisition.” VanPatten and Wong (2003) note that “Acquisition of a linguistic system is input dependent.” Krashen also takes a look at savants, polyglots and ordinary folk who have learned languages via comprehensible input in this fascinating paper. In a study of Spanish learners, comprehensible input teaching worked about six times as quickly as traditional instruction. There is a great short comprehensible input demo by Krashen here, and here (starts at about 12:30) is a longer and more detailed lecture.

Krashen also lists the academic research supporting comprehensible input here.

Ashely Hastings’ “Focal Skills” program (which presents first aural (and video), then written comprehensible input before moving into writing and speaking), was designed for use in Uni classes, and is where what we call “Movietalk” came from. The research on Focal Skills shows it much more effective than traditional present-and-practice approaches.

4) Should we organise curriculum thematically?NO. Among other reasons, it turns out that it’s harder to remember clusters of similar vocab than collections of thematically disparate vocab. As Paul Nation writes, “research on learning related vocabulary, such as lexical sets, … shows that learning related words at the same time [e.g. in thematic/semantic units such as “clothes” or “chores”] makes learning them more difficult. This learning difficulty can be avoided if related words are learned separately, as they are when learning from normal language use.” See Paul Nation on lexical sets and Rob Waring’s paper on vocab learning.

5) Should we “shelter” (limit) vocab? YES.Evidence from children’s language acquisition suggests that we should, while “upping” prosodic variation (“wacky” or differentiated voices), reading rituals, and responses to student output (the paper is forthcoming). There is some processing research (VanPatten) that suggests that the amount of “mental energy” available for comprehension is limited, and that a minimal amount of new vocab be introduced in structured patterns over a broad overlay of well-known vocab, so that “mental energy” can be devoted to acquiring newer items. VanPatten: “any model of L2 input processing [must] consider in some way the impact of capacity issues in working memory on what learners can do at a given point in time.” In other words, overload = bad.

Children also acquire vocabulary more quickly if it is “framed”: delivered in interactive, structured and limited speech-and-response sets (see chapter 10 of the interesting book Nurture Shock for details). It is estimated (Nation, 2006) that in most languages, the top 1000 most-frequently-used words account for about 85% of all oral language use, and the top 2000 for ~95%. Best practice is probably to teach “along the frequency list” where the most emphasis is on words that are most used (with variations that cater to student needs and interests).

6) Do learners “learn” grammar that teachers “teach?” Not on teachers’ or texts’ schedules. VanPatten (2010) argues in this very comprehensive paper that “some domains [aspects of language acquisition] may be more or less amenable to explicit instruction and practice [e.g.vocabulary], while others are stubborn or resistant to external influences [e.g. grammar].” VanPatten, echoing Krashen, concludes that there is limited transfer of conscious knowledge “about” language into functional fluency and comprehension, and notes that “[n]ot only does instruction not alter the order of acquisition, neither does practice” (2013).

Ellis (1993) says that “what is learned is controlled by the learner and not the teacher, not the text books, and not the syllabus.”

7) Should we use L1– the “mother tongue”– in class?YES, (albeit as little as possible), as Krashen notes, because this avoids both ambiguity AND incomprehensibility, neither of which help acquisition. Here are some ideas about why L1 should be used in the languages classroom (Immersion teachers take note…all the _______ in the world won’t help kids who do not understand it). Nation (2003) notes “There are numerous ways of conveying the meaning of an unknown word […] However, studies comparing the effectiveness of various methods for learning always come up with the result that an L1 translation is the most effective (Lado, Baldwin and Lobo 1967; Mishima 1967; Laufer and Shmueli 1997).”

8) Can we change the order of acquisition?NO. Krashen’s books have examples of order of acquisition. More recently, Lightbown and Spada (2013) reiterate Krashen’s contentions, showing how acquisition order of verb forms (in English-learning children) is fixed. Wong and VanPatten (2003) make the same point. There is very little we can do to “speed up” acquisition of any “foreign” grammar rule (e.g. English speakers learning the Spanish subjunctive) or vocabulary, other than providing lots of comprehensible input that contains the rule in question.

VanPatten (2013) notes that instruction “does not alter the order of acquisition,” and Long (1997) says that “[t]he idea that what you teach is what they learn, and when you teach it is when they learn it, is not just simplistic, it is wrong.” We also know that L2 mistakes are partially a function of L1, have partly to do with L1-L2 differences, but mostly to do with learners not being mentally ready to produce the new form (which is a result of a lack of input).

For example, L1 German learners of L2 French make mistakes with subject-verb inversion…despite German having exactly the same rule as French for s-v inversion. Arika Okrent documents children’s L1 acquisition errors; note that errors 5-8 are also classic adult L2 acquisition errors (stages).

Bardovi-Harlig (2000) found, as VanPatten and Wong (2003) put it, that “learners […] have demonstrated that acquisition of the tense and aspectual systems (e.g. the use of the preterit/passé composé and the imperfect) is piecemeal and unaffected by instructional intervention.” In Lightbown (1984), French-speaking students’ English output did not “match” the input they were given. Students “do not simply learn linguistic elements as they are taught– adding them one after another in neat progession. Rather, the students process the input in ways which are more “acquisition-like” and not often consistent with what the teacher intends for them to “learn”.”

9) Does correcting or properly re-stating learner mistakes–recasting– improve learner performance? NO. Lightbrown and Spada (2013) point out that while teachers like recasting (and do it a lot), and while students can and do immediately generate improved output as a result, “these interactions were not associated with improved performance on […] subsequent test[s].” VanPatten writes “[d]irect error correction by the instructor does not promote linguistic accuracy and the absence of error correction in the early stages of acquisition does not impede the development of linguistic accuracy” (1986, p. 212). Semke (1984) noted that increases in fluency and proficiency

My view: if there is a place for recasts in the languages classroom, it is in ensuring that student output– which is also input for other students— is comprehensible and accurate.

10) Is there broad agreement among second-language-acquisition researchers about what constitutes effective practice? YES. In this paper, Ellis lays out the “ten principles” of second languages teaching. He notes

comprehensible input is the sinequa non of second language acquisition

we must provide some “focus on form” (grammar explanations) to support meaning

there is no transfer from explicit knowledge of grammar to implicit language competence

the use of quite a lot of “formulaic” expressions– a.k.a. “lexical chunks”– is essential esp. for beginners

curricula organised along grammar sequential lines are probably not brain-friendly

instruction must primarily focus on meaning

drills don’t work

some output is necessary for acquisition in much later stages as this focuses learner attention on some aspects of form

S.L.A. researcher Patsy Lightbown here explains the “known facts” about second language acquisition. Here is a video of S.L.A. research and what works/does not work by Bill VanPatten.

11) Do “learning styles” or “multiple intelligences” exist? NO. In this paper, psychologist Daniel Willingham puts the boots to the idea that teachers need to kill themselves providing nineteen different ways to learn the verb “to run.” While people often have preferences about learning, and while some people definitely have better skills in some areas than others, there is no evidence to suggest that language acquisition is positively affected by anything other than the presence of masses of comprehensible input, and the absence of counterproductive activities (grammar practice, forced output, grammar lectures, etc).

VanPatten has said that “No research has found a link between learning styles and individual differences on the one hand, and on the other the processes involved in language acquisition.”

12) Do students like speaking in a second-language class? Generally, no. Krashen first made this point, and Baker and MacIntyre note that “Speaking has been found to be the most anxiety-provoking form of communication,” (references to Maclntyre & Gardner (1991) and McCroskey & Richmond (1987)) and also note that production anxiety in classes is high among non-Immersion students.

Best practice is probably to let those want to, talk, and to delay any output for others while asking them to signal comprehension or lack thereof (as natural approach, A.I.M., Narrative Paraphrase and T.P.R.S. do).

13) Does speaking improve acquisition? NO. Despite (a few) studies which try to make the case for output, there isn’t a strong one. See Krashen’s response to one such study here, and his examination of Swain’s output hypothesis– and the research testing it– here. In another study, English-speaking students were taught Spanish structures (subjunctive and conditional) via various mixes of input and practice output. In this study, students who

got input only did very well

got input and did limited output (“practise”) did no better than input-only students

did more output (“practise”) than getting input did significantly worse than those who got more input.

Wong and VanPatten (2003) note that “[a]cquisition of a linguistic system is input-dependent, meaning that learners must be engaged in comprehension in order to construct that system […] Production is not comprehension and thus produced language is not input for the learner. That input must come from others.” They also note that “drills are unnecessary and in some cases hinder acquisition,” and Van Patten (2013) remarks that “traditional ‘practice’ may result in language-like behaviour, but not acquisition” and that “practice is not a substitute for input.” He goes on to ask “if input is so important, what does traditional practice do?” and answers “essentially very little, if anything.It does not help mental representation. It is not clear it helps skills.”

VanPatten also says that when “mechanical drills attempt to get the learner to acquire the thing they are asked to produce, the cart has been put before the horse,” and notes that “research conducted since the early 1990s has shown that traditional approaches to teaching grammar that involve the use of mechanical, meaningful and communicative drills do not foster acquisition in the way that practice [listening/reading] with structured input does.”

14) Should we speak s.l.o.w.l.y. in class?YES. Audiologist Ray Hull writes “[f]or an adolescent, spoken speech at around 135 words per minute is perfect for speech understanding, particularly when the student is learning a new language. So, 130 WPM may be even better. It will seem very slow to you, but the central auditory system of the student will appreciate it.” Adult native-language output is 170-180 words per minute, so slowness is essential (for all teachers, not just those of languages). Note that there is no way to speed up auditory processing speed.

15) Do learners need many repetitions of vocab items to acquire them? YES. In this study, scientists concluded that 160 repetitions of an item resulted in new items being “wired in” like older (or L1) items. However, acquisition rates vary and depends on various factors: is the word an L1 cognate? Is it being used comprehensibly? Is its use meaningful?, etc.

16) Does feedback about performance in a language (e.g. correction, explicit information, etc) help acquisition? NO.Sanz and Morgan-Short (2002) replicated with computer-delivered input what VanPatten & Cadierno (1993) did with spoken and written input. And, as VanPatten & Wong (2003) put it, they found that “neither explicit information nor explicit feedback seemed to be crucial for a change in performance; practice in decoding structured input alone […] was sufficient.” In other words, explaining to people how a grammar rule in a language works, and/or pointing out, explaining and recasting (correcting) errors has no effect on acquisition. VanPatten also writes that “Overt correction does little good in the long run” but “indirect correction may be useful,” but notes that the research on indirect feedback is far from clear.

17) Are some people better language learners than others?NO. Older research (as Vanpatten, 2013, watch it here, video 5, says) suggested different people had different aptitudes. New research (VanPatten 2013b, 2014) suggests, echoing Krashen, that on traditional tests of aptitude that measure conscious learning— e.g. knowing grammar rules– there are “better” and “worse” students.

HOWEVER, in terms of processing (understanding) ability, there is no difference among people. If they get comprehensible input, they acquire at roughly the same rate, in the same way. A classroom that foregrounds grammar practice and output should produce a more varied mix of outcomes than one which focuses on input. VanPatten notes that working memory– roughly, how much “stuff” one can keep in their head consciously at a time– varies between individuals, and that those with greater working memory may find language acquisition easier.

18) Do children and adults learn languages in the same way? Mostly, yes. Children must develop a linguistic system while simultaneously acquiring a language. For example, kids need to develop basic competencies (which adults take for granted), such as knowing that words can represent reality, that that there are such things as individual words, etc. Once this “linguistic foundation” has been laid, kids and adults acquire languages in the same way. We know this because kids and adults make similar errors, have similar sequences of acquiring grammar, etc. As VanPatten notes, “adults and children appear to be constrained by the same mechanisms during language acquisition regardless of context, and the fundamental ingredients of language acquisition are at play in both situations: input (communicatively embedded language that learners hear or see, if sign language); Universal Grammar coupled with general learning architecture; and processing mechanisms that mediate between input and the internal architecture. In short, much of what we observe as differences between adults and children are externally imposed differences; not differences in underlying linguistic and psycholinguistic aspects of acquisition. And some of those externally imposed differences are a direct result of myths about language acquisition.”

19) Do we have data showing how well comprehensible input methods work in comparison with legacy methods? YES.(note: Nov 14, 2015– this section is being updated; please comment if you have things to add)

C.A.L.A. testing shows T.P.R.S.-taught students outperforming other students despite having less in-class time than other students

Joe Dziedzic found that T.P.R.S. outperformed “communicative” teaching, with the biggest gains for T.P.R.S.-taught students being in oral and written output, despite T.P.R.S. students not being forced to speak or write outside of evaluation.

Ray & Seely’s Fluency Through T.P.R. Storytelling (7th ed.) has a research appendix. Summary: T.P.R.S. never works worse than, sometimes performs as well as, but mostly performs better than traditional methods.